This application for a two year Geriatric Mental Health Academic Award renewal has the long-term objective of providing the Principal Investigator with a thorough understanding of, and experience with, clinical pathological correlation in psychogeriatric research. Towards that end, he will couple ongoing studies of the psychopathology of suicide in the elderly with the investigation of a likely neurobiological correlate to late life suicide -- hypothalamic-pituitary-adrenal (HPA) axis dysfunction. Based on an empirically derived model, the proposed studies test the hypothesis that late life suicide is a behavioral expression of neurobiological changes which result from age associated alterations in HPA axis feedback regulation. The specific aims of the proposal are to explore the state of the HPA axis in both completed and attempted suicides using a variety of neurochemical, molecular biological, and drug challenge techniques; to define the relationship of these neurobiological variables to psychiatric symptomatology and diagnosis; and, through long-term follow-up, to determine the relationship of HPA axis functioning to course of illness and outcome.